1. Field of Invention
The invention relates to an ink cartridge for storing ink therein to be supplied to an ink-jet head of an ink-jet recording device.
2. Description of Related Art
U.S. Pat. No. 6,270,207 B1 discloses an ink cartridge that includes a case having therein side partitioning walls and a bottom partitioning wall to divide the inside of the case into a first ink chamber, a second ink chamber and an atmosphere connection chamber. In the ink cartridge, the bottom partition wall has a connecting hole that connects the first chamber and the second chamber to each other. The opening of the connecting hole is circular in horizontal cross-section.
U.S. Pat. No. 6,074,051 discloses an ink cartridge that includes a cartridge case having a partition which partitions the cartridge case interior into an ink chamber and a storage chamber. The ink chamber contains ink, and the storage chamber contains a member impregnated with ink. The partition has an ink passage formed through it at its bottom to connect the ink chamber and the storage chamber.
The invention provides an ink cartridge wherein blocking of a connecting hole, which connects a porous member storage chamber and an ink chamber, by an air-bubble, is prevented, thereby effectively preventing ink leakage from an ink-jet head.
According to one aspect of the invention, an ink cartridge for storing ink to be supplied to an ink-jet head, includes a case having a partition therein for dividing an inside of the case into a first chamber and a second chamber, and a porous member is accommodated in the first chamber and impregnated with the ink. In the ink cartridge, the partition wall has a connecting hole that passes through the partition wall in a gravity direction when printing is performed by the ink-jet head. The connecting hole connects the first chamber and the second chamber in the gravity direction. The opening of the connecting hole has noncircular cross-section in a direction perpendicular to the gravity direction.
With this structure, the connecting hole is prevented from being closed by an air-bubble, so that ink stored in the first chamber and ink stored in the second chamber can always be in contact with one another. Accordingly, the ink in the ink chamber can be absorbed by the porous member at all times. Consequently, ink leakage from the ink-jet head can be effectively prevented.